Allright here we go... ABM Single bridges. After deciding to hold all the bridges in place and drill them all out together. I made some spacers to ensure I had equal spacing and keep the bridges square. Then I wrapped them with tape in a compensated position. I needed something to center the drill bit so I took my counter sink apart nad used it.
A picture of the spacers and the finished holes. If I had to do it again I would calculate out all the holes, mark them and drill. It worked well enough just not sure it was the greatest idea. The poplar is really hard to keep a bit from wandering in. This one has the maple neck tenon 1/4" down so the screws have plenty to bite into.